I'm on FM kit everything with E85 and 250hp roughly. I've done a Harris Hill Raceway (Austin,TX) track day and averaged about 6mpg; but it's a small track. I have 40 minutes of driving at Circuit of the America's this saturday and wondering what kind of fuel consumption I should get incase I need to bring spare fuel. Max I'll have 48 miles if I'm lucky. If I get worse gas mileage of 4mpg then I should consume 9.6 Gallons out of my 11.9g stock gas tank. So maybe bring 1x 5 gallon jug of E85 and I should be more than prepared I'm thinking. Anyone have any data to share on E85 consumption on big tracks?

 

Fuel consumption on track is usually measured in fuel/time not distance. Track layout should have little effect on this. If you burn 9.6 gal in 40 min of track time, budget 15 gal/hour of track time.

 

Exactly, fuel consumption in the track context is easier to calculate as gallons/hr like marine and aircraft.

Burn rate varies greatly depending on how much time is spent at full throttle, average RPM and the power output of the car so asking for other people's burn rate won't really help you. The only way to get usefully accurate data is to do at least a little bit of testing. If you don't trust a fuel gauge (you shouldn't) the most accurate way is to actually weigh the car. That's what we would do on our race cars once the engine tune was finalized. From there we had very accurate data on gallons per hour which would then be used for Ray strategy, particularly in Enduros.

Here is a handy formula to plug in your numbers once you've done some initial testing. How to Estimate Your Engine's Required Fuel Flow.

 

Thanks for the information. Turned out I’m not as flat out as I was thinking with 225 R888r. 24 miles has dropped tank gauge 1/4 tank. Since my day will comprise of 2x 20min sessions I’ll be fine. I keep thinking E85 is going to disappear, but I forget that it’s just 1.8L engine.

 

What kind of station do you get your E85 and % ethynol is it? We consistently get 82-84% at a Murphy express here in Fort Worth.

 

I get mine from a racetrack gas station in Dallas. It’s pretty crap and I’ll get content and update this. But considering I was tuned on this I never felt like hunting for better E85.

 

H2R has been closed for months! And it doesnt have much room for WOT in a boosted miata. CoTA will use much more gas I think.

 

Your right it's been a while since I've been to H2R. I drove about 50min on COTA which was 54 miles and gas gauge on level surface was halfway between 1/4 tank and 1/2 tank marks. Even on high load I never saw fuel starve, which is more than I can say for my S2000 I tracked for years.

 

Wicked, do you have a build thread? I need to get in more track time.

 

https://www.miataturbo.net/build-thr...oosted-100602/